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  • Writer's pictureMitchell Fotheringham

The Truth About Injected Damp Proof Courses: Why They're a Snake Oil Solution

Image of an injected DPC with a plant growing out of it showing that it is retaining moisture.

As a proud owner of a traditional building, you're likely aware of the challenges that come with maintaining its historic charm and integrity. One common issue that many traditional building owners face is dampness, which can lead to structural damage and the growth of harmful moulds. In the search for solutions, you may have come across injected damp proof courses (DPCs) - a treatment that claims to provide a quick fix. However, before you fall for the hype, let's take a closer look at why injected DPCs are nothing more than snake oil for traditional buildings.

First, let's understand what an injected DPC is. It involves injecting a chemical solution, typically silicone-based, into the walls of a building to create a barrier against moisture. The idea is that the injected DPC will prevent dampness from rising through the walls, thus solving the issue. However, this approach is fundamentally flawed and can cause more harm than good.

One of the main reasons why injected DPCs are bad for traditional buildings is that they go against the natural principles of how traditional buildings were designed and built. Traditional buildings, such as those constructed with solid masonry walls, were designed to allow moisture to evaporate from the walls rather than trapping it inside. These buildings are built with moisture-open materials, such as lime mortar, masonry units such as sandstone and soft bricks, which can absorb and release moisture. Injecting a DPC disrupts this natural process, trapping moisture inside the walls and preventing them from "breathing." As a result, the moisture can accumulate and cause further damage over time, such as increased salt crystallization and spalling of masonry units, which can lead to irreversible damage to the building fabric.

Another reason why injected DPCs are ineffective is that they only address the symptoms of dampness rather than addressing the root cause. Dampness in traditional buildings is often caused by other issues, such as defective guttering, leaking roofs, or high ground levels, which result in water ingress. Injected DPCs do not address these underlying issues and only provide a temporary solution by creating a barrier in the walls. This means that the dampness may continue to persist and cause damage, even after the DPC treatment is applied, leading to a false sense of security and wasting your time and money on a temporary fix.

Moreover, the long-term effectiveness of injected DPCs is highly questionable. Many studies and experts in the field of conservation and historic building preservation have questioned the effectiveness of injected DPCs in traditional buildings. There is a lack of scientific evidence and long-term studies to support their claims, and the majority of studies conducted have shown that the success rate of injected DPCs is low, and the treatment often fails after a few years.

In addition to being ineffective, injected DPCs can also be costly. The process of injecting chemicals into the walls can be invasive, requiring the removal of skirting boards, plaster, and other finishes, which can damage the historic fabric of the building and result in additional costs for repairs and restoration. Considering the lack of long-term effectiveness, the cost of injected DPCs can be a waste of money and resources.

Injected, damp-proof courses are nothing more than snake oil for traditional buildings. They go against the natural principles of how these buildings were designed and built, disrupt the building's natural ability to "breathe," only address the symptoms of dampness, and lack scientific evidence of their long-term effectiveness. Instead of relying on quick-fix solutions, it's important to address the underlying causes of dampness in traditional buildings, such as addressing water ingress issues, improving ventilation, and using moisture-open materials. Consulting with conservation and historic building experts is crucial to ensure that the appropriate preservation methods are applied to protect the historic fabric of the building.

Preserving traditional buildings requires a holistic approach that considers the building's unique characteristics and historic construction methods. Injected DPCs, with their short-term effectiveness, lack of scientific evidence, and potential for further damage, are not a viable solution for addressing dampness in traditional buildings. Instead, it's important to work with conservation professionals who understand the complexities of traditional building preservation and can recommend appropriate strategies that respect the building's original design and materials.

So, if you're considering injected DPCs as a solution for dampness in your traditional building, think again. Don't fall for the snake oil claims of a quick fix. Instead, invest in proper investigation and diagnosis of the underlying causes of dampness, and work with experienced conservation professionals to develop a comprehensive and appropriate plan for preserving your traditional building.

In conclusion, when it comes to injected DPCs for traditional buildings, don't believe the hype. These treatments can disrupt the principles of traditional buildings, only provide temporary relief, lack scientific evidence of long-term effectiveness, and can be costly. It's essential to take a holistic approach to building conservation, considering the unique characteristics and construction methods of traditional buildings and working with conservation professionals to develop appropriate strategies for long-term preservation. Don't be swayed by quick fixes - protect your traditional building with informed decision-making and proper conservation methods.

Get in touch with us today to discuss your requirements; call us on 0141 237 9491 or email us

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